The invention discloses a
tin-free weather-resistant hydroxyl
polyester resin and a preparation method thereof, and belongs to the technical field of hydroxyl
polyester resin, the preparation method comprises the following steps: firstly, carrying out acid
pickling and calcining pretreatment on diatomite, then carrying out KH-550
silane coupling agent modification,
cerium loading and
behenic acid hydrophobic modification to obtain a
cerium-loaded hydrophobic modified diatomite catalytic
promoter, and finally, carrying out acid
pickling and calcining treatment on the
cerium-loaded hydrophobic modified diatomite catalytic
promoter to obtain the
tin-free weather-resistant hydroxyl
polyester resin. Then taking polybasic acid and polyhydric
alcohol as monomers, adding an
ethylene glycol
titanium catalyst and a
hydrolysis-resistant catalytic
promoter, and performing normal-pressure esterification and high-vacuum
polycondensation reaction to prepare the
tin-free weather-resistant hydroxyl
polyester resin; on the basis of tin-free treatment, through
synergistic catalysis of the
ethylene glycol
titanium catalyst and the cerium-loaded hydrophobic modified diatomite catalytic promoter and structural optimization of the rigid
monomer, the technical problems that a traditional
titanium catalyst is poor in low-temperature
dispersity and prone to
hydrolysis and deactivation in advance are effectively solved, the stability of a catalytic
system and the
processing performance of resin are improved, and the service life of the resin is prolonged. The weather-resistant
polyester resin is suitable for weather-resistant
polyester resin scenes for
powder coatings such as high-end outdoor building materials and automobile hubs.